Saturday, February 28, 2009

Some charts of the falling Case-Shiller Housing Index

The latest Case-Shiller home price index came out earlier this week. They show decreases in the 20 city composite of 2.5% November 2008 to December, and the most damning statistic is the decline of 26.7% from the housing peak in 2006.

The results are more obvious visually. I think the relevant comparison is from today's prices to the earlier peaks. Here is the full data for all of the cities (click the picture for larger) showing data from 1987 to today. The index is 100 in 2000. The peak is quite obvious and the current fall off even more so.

I took the indices after the peak and looked at the % decrease as a fraction of the peak index, essentially using the peak as the basis. The numbers look even scarier then.

The places in which home values have evaporated the most dramatically are cities in California, cities in Florida, Phoenix and Las Vegas. The California housing bust seems to be a combination of speculation and general California high home values. The other cities appear to reflect a bust in speculation on vacation homes and second homes. Detroit stands out as an example of a city whose housing prices are gutted because the car industry that built the city has fled.

Another way to see what places are down a lot and what places are down a little is to look at a map.
Here the are of the bigger circle is the index at the peak, and the area of the circle inside is the index in December. The more the circles shrink the more the value is lost. I like this view more than the percentages because you can see that, for instance, Detroit has lost a lot but they weren't as high as the cities in California or Florida, so there is more value per house being lost in the California cities than in Detroit.

I suppose that because it was a housing bubble, it eventually had to burst and was built on speculation rather than a sustainable increase in value. The question is how far will it burst.


Howard said...

Did you create these graphs? If so, what did you use to do so, particularly for the last one.

Richard said...

I used excel to make the graphs. The first two graphs were simple. The last graph is kind of cobbled together.

I got the latitude and longitude of the target cities from the web and then used those as y and x for the bubble charts where the size of the bubble for the first data set is the peak index and the bubbles for the second data set (y's and x's the same as the first) is the dec 2008 index. I had excel add labels and replaced the numbers in each label with the name of the city, typing by hand. I tried laying that chart over a map of the US but no map matched my set no matter the stretching and contracting. I then just took the bubbles of the cities and placed them on the approximate location of the US using MS Paint. It was not seamless and I need a way to plot this kind of data on a map in excel. If I had a data set of the outlines of the US and states I could have plotted that and then plotted the bubbles on top. I will need to look for one.

Howard said...

I have not played with it but can do some interesting graphs, including maps.